Authorizations for the Use of Force, International Law, and the Charming Betsy Canon

Abstract

International law has figured prominently in several on-going disputes around actions of the U.S. military in Afghanistan, Iraq, Guantanamo, and here in the United States, but the precise relationship between international law and President's war powers has nonetheless gone largely unexplored. This Article seeks to clarify one important aspect of that relationship: the role of international law in determining the scope of Congress's general authorization for the use of force. Recent cases, including Hamdi v. Rumsfeld, 124 S. Ct. 2633 (2004), have confirmed the importance of congressional authorization to the Court's construction of the President's war powers. International law can, in turn, play an important role in how courts interpret the scope of general authorizations for the use of force by Congress. The plurality opinion in Hamdi illustrates this point, but unfortunately relies on international norms without sufficient attention to their content or their relationship to the authorization provided by Congress. This article identifies and defends a better approach: courts should presume that general authorizations for the use of force do not empower the President to violate international law. Such a presumption is consistent with long-standing tools of statutory interpretation reflected in the so-called Charming Betsy canon, does a good job of maximizing the presumed preferences of Congress, advances separation of powers in a number of ways, and promotes several normative values that favor the use of international law as an interpretive tool.

Keywords: War Powers, President, Congress, Foreign Affairs, Hamdi, International Law, Treaties, Separation of Powers, Charming Betsy

JEL Classification: K33